Training a few dogs and surrounding your MCV with walls is a good way to start. The dogs can be used for scouting the map and your enemy, allowing you to react to threats earlier. Walls will prevent the cheaper AI tactics such as engi rushes.
Unlike vanilla YR, the AI will use siege weapons properly, so keep in mind you can't just build defenses and let the AI walk into them.
A very common mistake is people (including me) simply sitting on their credits. You should always be producing something in all tabs if you can. 100k+ credits in the bank won't help you when you have Kirovs knocking on your door.
Building more of the same production structure will increase the speed that units are produced from that strucutre. Tanks not building fast enough? Build another War Factory or two.
Bear with us, we'll be toning down the AI in the next version for all difficulties except Mental.
AI can siege right? good to know XD. thanks for the input mr.meister!